1. Field of the Invention
The present invention relates to an inkjet printing apparatus, and more particularly, relates to adjustment of the temperature of ink circulating the inkjet printing apparatus.
2. Description of the Background Art
Japanese Patent Published Application No. 2006-88575 discloses an ink jet printer in which ink is circulating. In the case of this type of ink jet printers, warranty temperature ranges are defined to ensure print quality for example as described in Japanese Patent Published Application No. 2004-276486.
Because of this, in this type of ink jet printers, it has been proposed to provide a heater for heating ink when the ink temperature has descended below the warranty temperature range and a cooler for cooling the ink when the ink temperature has risen above the warranty temperature range.
However, the heater and the cooler are devices for performing opposing operations. Because of this, the heating efficiency of the heater is often degraded by the provision of both the heater and the cooler. For example, while the cooler is provided with a heat sink and a fan, heat dissipation occurs from ink at the heat sink during heating the ink by the heater when the ink temperature is too low, so that the heating efficiency is degraded. Also, since the ink has to be passed through the heater and the cooler, the circulation route of the ink becomes long, so that the amount of ink increases in the circulation route. Because of this, it takes much time to heat the ink to an appropriate temperature by the heater.